From the bridges of Porto to its estuary, two men are paying tribute to the elegant Douro River. Through LuΓs de CamΓ΅es and Prince Henry the Navigator, through its Viking ships and dizzying bridges, the Douro is a great witness to the history and culture of Portugal. Jean Rouch and Manoel de Oliveira are walking alongside while reciting a poem written by de Oliveira himself. During their walk, they reflect upon documentary-making, the charm of the river, and what it represents to them.